Faeces
A protein and biological soil where the hygiene question and the stain question have different answers, and the hygiene one comes first.
In detail
Faecal soiling is unusual among household soils because the visible mark is the lesser problem. It carries bacteria and, on textiles and soft furnishings, the residue continues to break down after the mark has gone, which is what produces recurring odour and, with pets, repeat marking of the same spot. The order of operations is therefore hygiene first, appearance second. Solids are removed mechanically before anything is wetted — a wet method applied over solids spreads them and drives them into the structure. The carpet institute's entry then runs a detergent solution, a spot removal kit, a vinegar solution, warm water and an ammonia solution, which is the protein branch. Two cautions are worth stating. Ammonia is a component of urine, so an ammonia-based treatment on a pet accident can reinforce the scent cue that brings the animal back, which is why an enzymatic product is usually the better choice on a pet soiling even though the trade sequence names ammonia. And a chlorine bleach must not be used on a urine-contaminated surface, because bleach and ammonia produce chloramine gases — a serious and well-documented domestic hazard.
Why
- Faeces is explained by Protein denaturation
- Faeces is explained by Adsorption of odour molecules
Sources for this page
Sources
Spot Solver: spot and spill removal procedures
The Carpet and Rug Institute (CRI) · Trade or professional body
Relied on for: That the faeces entry runs a detergent solution, a spot removal kit, a vinegar solution, warm water and an ammonia solution. (states this directly)
Right to Know Hazardous Substance Fact Sheet: Ammonia
New Jersey Department of Health · Government or regulator
Relied on for: That ammonia reacts with hypochlorite bleach to produce chloramine gases. (inferred from the source; not stated directly)